title: Hypofractionated radiation therapy for breast ductal carcinoma in situ.
abstract: OBJECTIVE
  Conventional radiation therapy (RT) administered in 25 fractions after breast-conserving surgery (BCS) is the standard treatment for ductal carcinoma in situ (DCIS) of the breast. Although accelerated hypofractionated regimens in 16 fractions have been shown to be equivalent to conventional RT for invasive breast cancer, few studies have reported results of using hypofractionated RT in DCIS.
  
  
  METHODS
  In this multicenter collaborative effort, we retrospectively reviewed the records of all women with DCIS at 3 institutions treated with BCS followed by hypofractionated whole-breast RT (WBRT) delivered in 16 fractions.
  
  
  RESULTS
  Between 2003 and 2010, 440 patients with DCIS underwent BCS followed by hypofractionated WBRT in 16 fractions for a total dose of 42.5 Gy (2.66 Gy per fraction). Boost RT to the surgical bed was given to 125 patients (28%) at a median dose of 10 Gy in 4 fractions (2.5 Gy per fraction). After a median follow-up time of 4.4 years, 14 patients had an ipsilateral local relapse, resulting in a local recurrence-free survival of 97% at 5 years. Positive surgical margins, high nuclear grade, age less than 50 years, and a premenopausal status were all statistically associated with an increased occurrence of local recurrence. Tumor hormone receptor status, use of adjuvant hormonal therapy, and administration of additional boost RT did not have an impact on local control in our cohort. On multivariate analysis, positive margins, premenopausal status, and nuclear grade 3 tumors had a statistically significant worse local control rate.
  
  
  CONCLUSIONS
  Hypofractionated RT using 42.5 Gy in 16 fractions provides excellent local control for patients with DCIS undergoing BCS.
authors.affiliation: Department of Radiation Oncology, Hôpital Maisonneuve-Rosemont, Centre affilié à l'Université de Montréal, Montreal, Quebec, Canada.
authors.forename: Lara
authors.initials: L
authors.lastname: Hathout
authors.forename: Tarek
authors.initials: T
authors.lastname: Hijal
authors.forename: Valérie
authors.initials: V
authors.lastname: Théberge
authors.forename: Bernard
authors.initials: B
authors.lastname: Fortin
authors.forename: Horia
authors.initials: H
authors.lastname: Vulpe
authors.forename: Jean-Charles
authors.initials: JC
authors.lastname: Hogue
authors.forename: Christine
authors.initials: C
authors.lastname: Lambert
authors.forename: Houda
authors.initials: H
authors.lastname: Bahig
authors.forename: Louise
authors.initials: L
authors.lastname: Provencher
authors.forename: Peter
authors.initials: P
authors.lastname: Vavassis
authors.forename: Michael
authors.initials: M
authors.lastname: Yassa
mesh_terms: D000367:Age Factors; D001943:Breast Neoplasms / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D018572:Disease-Free Survival; D019583:Dose Fractionation, Radiation; D005260:Female; D006801:Humans; D015412:Mastectomy, Segmental; D008875:Middle Aged; D015999:Multivariate Analysis; D060787:Neoplasm Grading; D009364:Neoplasm Recurrence, Local / Q000401:mortality / Q000473:pathology; D018365:Neoplasm, Residual; D016609:Neoplasms, Second Primary / Q000401:mortality / Q000473:pathology; D017697:Premenopause; D011792:Quebec; D019233:Retreatment / Q000379:methods; D012189:Retrospective Studies; D018570:Risk Assessment; D016896:Treatment Outcome